.login_box {
  height: 100%;
  background: url('./bg.png') no-repeat center;
  /* 将背景图片按照容器的大小铺满整个屏幕 */
  background-size: cover;
}
.form_box {
  width: 420px;
  height: 460px;
  background-color: #fff;
  border-radius: 30px;
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  padding: 30px 28px;
  margin-top: 8px;
}
.form_box img {
  display: block;
  margin: 0 auto;
  margin-bottom: 30px;
}